Why do my headlights auto adjust when stopped behind another vehicle they move up and down constantly.  It looks irritating to driver in front but when vehicle moves further forward they stop adjusting.

That should not happen, I would get that investigated as would be a MOT issue it it happens, it’s normal for them to Cycle up and down upon car startup but that should be it 

Sounds like height level adjustment is damaged, seized or malfunctioning. There’s a little swivel arm sensor on the passenger side front and rear suspension. As car is loaded, it’s adjusts headlight height. It adjusts on start-up when headlights switched on, if it’s doing it all the time, something is broken. A scan with VCDS will reveal or whip the wheels off and take visual look.

Thanks for this,that would explain a lot as I have recently had 3 out of four springs changed after MOT failure, so possibly damaged or loose after repair to springs.

1 hour ago, Beats said:

 I have recently had 3 out of four springs changed after MOT failure,

Be aware that one should only change springs for matched pairs because of their gradual deformation with age.